Fetal Lung Development

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Fetal Lung Development

• Five stages in human
• Embryonal Stage
• Pseudoglandular Stage
• Canalicular Stage
• Saccular Stage
• Alevolar Stage

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Fetal Lung Development

• Five stages in human
• Embryonal Stage
• First 2 months
• Bud from pharynx
• Day 26 52
• Development of Trachea/major bronchi

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Fetal Lung Development

• Five stages in human
• Pseudoglandular Stage
• Day 52- Week 16
• Development of remaining conducting airways

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Fetal Lung Development

• Five stages in human
• Canalicular Stage
• Week 17 Week 28
• Development of vascular bed
• Framework of Acinus

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Fetal Lung Development

• Five stages in human
• Saccular Stage
• Week 20 Week 36
• Increased complexity of saccules

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Fetal Lung Development

• Five stages in human
• Alevolar Stage
• Week 36 Term
• Development of alveoli

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Fetal Lung Development

• Postnatal Lung Growth
• Factors affecting metabolic rate
• Nutrition deprivation
• Emphysematous changes
• Oxygen toxicity
• Bronchopulmonary dysplasia
• Hyaline membrane
• Cigarette smoke
• Reduced lung to body weigh ratio
• Hormonal
• Larger/fewer alveoli

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Fetal Lung Development

• Alveolar Cell Development
• Type I pneumocytes
• Squamous cells
• Thin gas permeable membrane
• 97 of alveolar surface area
• Type II pneumocytes
• Cuboidal cells
• Surfactant production
• Precusors to surfactant synthesis

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Fetal Lung Development

• Alveolar Cell Development
• Surfactant
• Lower surface tension w/in alveolus
• Blend of phospholipids